Roland Turner

Yahi Haze Mapping
about | contact

PDFtk awesomeness for scanning

Our office scanner has been cunningly designed so as to have an automatic document feeder, but to only be capable of scanning the upward-facing side of each page! Here are two PDFtk commands to help deal with this. Simple concatention: pdftk in*pdf cat output out.pdf Collation with the backs in reverse order, because when the stack is turned over to scan the backs, it scans the last page first: pdftk A=fronts.pdf B=backs.pdf shuffle A Bend-1... (more)

Word, "Changing the number format for this list updates the style"

None of the helpful guidance for this message from Microsoft Word pointed out that the underlying problem is that "Automatic Update" is turned on on various of the style elements in the template, so e.g. changing a bulleted list to a numeric list changes all of the lists in the entire document, but also numbering mysteriously fails to reset. Quite why anyone would do such a thing is a mystery to me, but the fix... (more)

Android Player and File Names with Colons or Digits in them

I created some MP3 files containing a talking clock to use in my phone's morning alarms and called them things like 6:30.mp3. When I tried to add them as alarm tones, I saw: Sorry, the player does not support this type of audio file. As they were only a handful of small files, freshly generated with LAME, and transferred via Dropbox, file corruption seemed rather unlikely. A little searching turned up a comment about filenames... (more)

First Gpredict Session

For the first time since July I managed to get out and operate last night. Sadly I made no successful contacts: During the 20:56 - 21:08 pass of CUTE-1.7 + APD II (21° peak) my TH-F7E radio went into a mode that I've never seen before. By the time I'd worked out how to reset it without wiping its memory ("Fn+Pwr" for future reference...) the pass was over. The other two passes that occurred while... (more)

Crash-Only Software at Papers We Love Singapore

I gave an overview of Candea and Fox's Crash-Only Software at Papers We Love Singapore last night. The slides are a little spartan. (more)

Brexit, Interrupted (UPDATED - This approach won't work.)

Update: 2016-11-06 Writing up an idea in detail can be an effective way to share it, but also to more quickly discover any errors in it by giving others the opportunity to scrutinise it. In this case, a significant error in my understanding of the role of the Supreme Court has been pointed out to me, large enough that the approach described below clearly won't work. The only judicial function that the House of Lords... (more)

Simplest Possible Systemd Service

(Because almost every search result for this provides a lengthy discussion instead of a simple example...) In /etc/systemd/system/sleep-92951829.service : [Unit] Description=Sleep Demo [Service] ExecStart=/bin/sleep 92951829 [Install] $ sudo chown root.root /etc/systemd/system/sleep-92951829.service $ sudo chmod 644 /etc/systemd/system/sleep-92951829.service $ sudo systemctl enable sleep-92951829 $ sudo systemctl start sleep-92951829 $ ps -fC sleep (more)

PayPal problem VV44REXSG (KMM201394745V73460L0KM) and the lack of a Singapore remittance license

3 years ago, PayPal ceased handling payments from Singapore account holders to charities outside of Singapore. The cited reason is that PayPal does not hold a remittance license in Singapore. An important consequence of this is that payments from Singaporean PayPal accounts to any non-profit organisation outside of Singapore, charitable or otherwise, are prevented. Inconveniently, and despite the fact that this is not a secret at all, PayPal appears unwilling to correctly describe the reason... (more)

First successful satellite tracker test

(Photo: Darryl Ee 9V1DE) After successfully listening to FO-29 with a handheld satellite-antenna at Geekcamp last year, I realised two things: directional antennas are extremely desirable for satellite work, but holding and pointing the antenna array by hand is exhausting. I therefore decided to build a tracker that would automate the pointing and following work. The resulting system came together just in time for Maker Faire, so I conducted its first tests on site. It... (more)